Answer:
-39.2m/s
Explanation:
Using the equation of motion;
v = u + at
Since the ball is thrown upward, the acceleration due to gravity acting on it will be negative, hence a = -g
v = u - gt
Since g = 9.8m/s²
t = 4.0s
u = 0m/s
v = 0 + (-9.8)(4)
v = 0 + (-9.8)(4)
v = -39.2m/s
Hence the speed of the ball before release is -39.2m/s
What does a model of a light wave tell us about
brightness and color?
Answer:
A wave model of light is useful for explaining brightness,color, and the frequency-dependent bending of light at a surface between media. However, because light can travel through space, it cannot be a matter wave, like sound or water waves.
Atoms of which two elements could combine with atoms of chromium (Cr) to
form ionic bonds?
O A. F.
B. Au
C. Se
D. Ti
E. Mg
Answer:
D and E
Ionic bonds are formed between metals and non-metals and both of those are metals
If a rock displaces 7 ml of water, what is the volume of the rock?
Answer:
if i am not mistaken the volume is 7, because it only took that much space
An Na ion has a charge of +1 and an Oion has a charge of -2. How many Na ions does one Oion need to balance
charges?
a system absorbs 500J of heat and at the same time 400J of work is done on the system what is change in internal energy
This is the solution of the problem. The problem is calculated from a closed system energy balance equation
Explain the meaning of work done and give examples
Answer:
the situation in which the force or any kinds of things rhat are done by force is called work done.ex.typed,wrote
Answer:
WORK DONE on a body is the product ofFORCE IN THE DIRECTION OF DISPLACEMENT AMD DISPLACEMENT.WORK ONLY HAS MAGNITUDE AND NO DIRECTION.
FORCE applied IN the direction of displacement × displacement = POSITIVE WORK DONEFORCE applied OPPOSITE to the direction of displacement × displacement = NEGATIVE WORK DONEFORCE applied PERPENDICULAR to the direction of displacement × displacement = ZERO WORK DONEhope it helps
have a nice day
Which of the following situations would violate the second law of
thermodynamics?
O A. A heat engine feeling cold after running for an hour
B. A heat engine using heat to do work
O C. A heat engine losing some energy as heat
D. A heat pump being 80% efficient
Answer: it’s A.
Explanation: A pex
A single loop of wire with an area of 0.0780 m2 is in a uniform magnetic field that has an initial value of 3.80 T, is perpendicular to the plane of the loop, and is decreasing at a constant rate of 0.240 T/s .
Requried:
If the loop has a resistance of 0.700Ω. Find the current induced in the loop.
Answer:
The induced current is 26.7 mA
Explanation:
Given;
area of the loop, A = 0.078 m²
initial magnetic field, B₁ = 3.8 T
change in the magnetic field strength, dB/dt = 0.24 T/s
The induced emf is calculated as;
[tex]emf = - \frac{d \phi}{dt} \\\\emf = -\frac{dB.A}{dt} \\\\emf = A (\frac{dB}{dt} )\\\\emf = 0.078(0.24)\\\\emf = 0.0187 \ V[/tex]
The resistance of the loop = 0.7 Ω
The induced current is calculated as;
[tex]V = IR\\\\I = \frac{V}{R} = \frac{emf}{R} = \frac{0.0187}{0.7} = 0.0267 \ A = 26.7 \ mA[/tex]
two groups of students carry out experiments to investigate the relationships between force and extenstion
Answer:
They investigated Hooke's law.
Explanation:
[tex]{ \tt{force \: \alpha \: extension }} \\ { \boxed{ \bf{F = kx}}} \\ x \: is \: extension \\ F \: is \: force \\ k \: is \: constant : k = 1[/tex]
When an AC source is connected across a 17.0 Ω resistor, the output voltage is given by Δv = (190 V)sin(50πt). Determine the following quantities. (a) maximum voltage V (b) rms voltage V (c) rms current A (d) peak current A (e) Find the current when t = 0.0045 s.
Explanation:
the answer is in the above image
(a) The maximum voltage V is 190 Volts.
(b) The rms voltage V is 95√2 Volts.
(c) The rms current in Amperes is 7.9 A.
(d) The peak current Amperes is 11.18 A.
(e)The current when t = 0.0045 s is 7.26 A.
What is current?The current is the stream of charges which flow inside the conductors when connected across the end of voltage.
Given is an AC source is connected across a 17.0 Ω resistor, the output voltage is given by Δv = (190 V)sin(50πt).
(a) From the given voltage equation, maximum voltage V is 190 Volts.
(b) rms voltage =Vmax/√2
Put the values, we get
Vrms = 190/√2 = 95√2 Volts
(c) rms current = Vrms/Resistance
Put the values, we get
Irms = 95√2 /17
Irms = 7.9 Amperes.
(d) peak current =√2 Irms
Substitute the values, we get
Peak current = 7.9 √2 = 11.18 A
(e) The current when t = 0.0045 s is written as
I = (190 V)sin(50πt)/R
Substitute the values, we have
I = (190 )sin(50π x0.0045)/17
I = 7.26 A.
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If it were to snow in Phoenix in July, which type of Earth scientist would be most
surprised?
Answer:
Economists, I guess.
Explanation:
In the figure below, this “double” nozzle discharges water (at 10°C, density= 1000 kg/m3) into the atmosphere at a rate of 0.50 m3/s. The pressure at the inlet is to be 315612 Pa. If the nozzle is lying in a horizontal plane. Jet A is 10 cm in diameter, jet B is 12 cm in diameter, and the pipe (1) is 30 cm in diameter. The x-component of force (Rx) acting through the flange bolts is required to hold the nozzle in place is:
Answer:
gfxfhhnhgfhjjgfghjhffgkhfdcg
What is the magnitude of a vector that has the following components: x = 32 m y = -59 m
Answer:
Explanation:
Since the x and y components are given
The vectors Magnitude = √32²+(-59)²
=67.12m
Một mol khí đang ở điều kiện tiêu chuẩn thì bị nén váo một bình 5 lít. Nhiệt độ khí trong bình là 770 C. Tính áp suất khí?
Đáp án:
p=5,74atm
Giải thích các bước giải:
áp suất khí là:
pV=nRT⇒p=nRTV=1.0,082.(77+273)5=5,74atmpV=nRT⇒p=nRTV=1.0,082.(77+273)5=5,74atm
p=5,74atm
Giải thích các bước giải:
áp suất khí là:
pV=nRT⇒p=nRTV=1.0,082.(77+273)5=5,74atmpV=nRT⇒p=nRTV=1.0,082.(77+273)5=5,74atm
The first charged object is exerting a force on the second charged object. Is the second charged object necessarily exerting a forcer on the first?
Answer:
Explanation:
Of course because it's Newton's Law that if body A exerts force on body B, then body B will exert equal but opposite force on body A.
HAPPY LEARNING:)
The first charged object is exerting a force on the second charged object. The second charged object necessarily exerting a force on the first is correct.
What is force?A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
Newton's third law states that for every action (force) in nature there is an equal and opposite reaction, from that we can understand when force is exerted on first charged object is exerting a force on the second charged object. The second charged object necessarily exerting a force on the first.
The first charged object is exerting a force on the second charged object. The second charged object necessarily exerting a force on the first is correct.
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Got it never mind. The only reason I'm typing more is to fill out the required space
Answer:
hey. i dont know what you tryna say but if u replying to someone else, you should use the comments section. in that way you won't lose points.
THE ANSWER!!! Please
Answer:
I think -7 N. Netforce is 3N-10N= -7N
Explanation:
A 9V battery is connected to two light bulbs. If the current through the circuit is 1.5 A, what is the resistance of each light bulb (assume both light bulbs are identical)?
Answer:
3 ohm
Explanation:
Given :
V=9V
And according to given question same current is flowing in both resistance that means resistance will connected in series
So,
R= R+R=2R
Now,
Applying ohm's law
[tex]V=IR\\9=1.5*2R\\9=3R\\R=\frac{9}{3} \\R= 3ohm[/tex]
Therefore, answer is 3 ohm
A given wave has a wavelength of 1.4 m and a frequency of 2.0 Hz. How fast
is the wave moving?
O A. 0.6 m/s
O B. 3.4 m/s
O C. 0.7 m/s
D. 2.8 m/s
Answer:
The wave speed is 2.8 m.
Explanation:
Wavelength = 1.4 m
frequency, f = 2 Hz
the wave speed is given by
wave speed = wavelength x frequency
wave speed = 1.4 x 2 = 2.8 m
option (D) is correct.
Một vật chuyển động tròn đều có chu kì T = 0,25 s. Tính tần số chuyển động f của vật?
Explanatio
omega=2pi/T
Answer:
0
0000
Explanation:
A caterpillar climbs up a one-meter a wall. For every 2 cm it climbs up, it slides down 1 cm. It takes 10 minutes for the
caterpillar to climb to the top. What is the distance traveled? (Round the number to the nearest hundred.)
cm
Answer:
1.5 m is ur answer
Explanation:
Scientists studying an anomalous magnetic field find that it is inducing a circular electric field in a plane perpendicular to the magnetic field. The electric field strength 1.5 m from the center of the circle is 7 mV/m.
Required:
At what rate is the magnetic field changing?
This question is incomplete, the complete question is;
Scientists studying an anomalous magnetic field find that it is inducing a circular electric field in a plane perpendicular to the magnetic field. The electric field strength 1.5 m from the center of the circle is 7 mV/m.
At what rate is the magnetic field changing?
Answer:
the magnetic field changing at the rate of 9.33 m T/s
Explanation:
Given the data in the question;
Electric field E = 7 mV/m
radius r = 1.5 m
Now, from Faraday law of induction;
∫E.dl = d∅/dt
E∫dl = A( dB/dt )
E( 2πr ) = πr² ( dB/dt )
( 0.007 ) = (r/2) ( dB/dt )
( 0.007 ) = 0.75 ( dB/dt )
dB/dt = 0.007 / 0.75
dB/dt = 0.00933 T/s
dB/dt = ( 0.00933 × 1000) m T/s
dB/dt = 9.33 m T/s
Therefore, the magnetic field changing at the rate of 9.33 m T/s
If energy is transferred spontaneously as heat from a substance with a temperature of T1 to a substance with a temperature of T2, which of the following statements must be true?
1-T1 < T2
2-T1 = T2
3-T1 > T2
4-more information is needed
Answer: The statement [tex]T_{1} > T_{2}[/tex] must be true.
Explanation:
As it is given that heat is being transferred from a substance with temperature [tex]T_{1}[/tex] to a substance with temperature [tex]T_{2}[/tex].
It is known that heat will always being transferred from a higher temperature to a lower temperature. Because at higher temperature the molecules of a substance acquire more energy and when they lose energy then a decrease in temperature occurs.
Hence, in the given situation [tex]T_{1} > T_{2}[/tex].
Thus, we can conclude that the statement [tex]T_{1} > T_{2}[/tex] must be true.
In 1913 Niels Bohr formulated a method of calculating the different energy levels of the hydrogen atom.
a. True
b. False
Two uncharged metal spheres, spaced 25.0 cm apart, have a capacitance of 26.0 pF. How much work would it take to move 12.0 nC of charge from one sphere to the other? Answer in Joules.
Answer:
Use 2>60n to get 19>089
Explanation:
Which of the following phenomenon odd called photoelectric effect?
A. High energy electrons impinge on a metallic Annie which emits electrons
B. A high energy photon emits photons as it slows down
C. A metal absorbs a quanta of light and then emits electrons
D. Two electrons are created from a quanta of light.
two electrons are created from a quanta of kight
Three resistors (16 ohm, 16 ohm and 8 ohm) are connected in parallel. The equivalent
resistance (Re)
Answer:
4 ohm
Explanation:
The equivalent resistance (Re) of three resistors in parallel is given by;
1/Re = 1/R1 + 1/R2 + 1/R3
Where; R1 = 16 ohm, R2 = 16 ohm, R3 = 8 ohm
1/Re= 1/16 + 1/16 + 1/8
1/Re= (0.0625) + (0.0625) + (0.125)
Re= 4 ohm
Two oppositely charged objects are separated by a small distance. The objects are then moved three times farther apart from each other. Which of the following statements best describes what happens to the electrical force between the objects?
A: The force of attraction increases
B: The force of attraction decreases
C: The force of attraction stays the same
D: The force of attraction becomes a force of repulsion
The statement best describes what happens to the electrical force between the objects when moved three times farther apart from each other is the force of attraction decreases. The correct option is B.
What is force of attraction?
The objects when placed at a distance, they are attracted by the gravitational force of attraction.
Gravitational force of attraction is directly proportional to the product of masses and inversely proportional to the square of distance between them.
Two oppositely charged objects are separated by a small distance. The objects are then moved three times farther apart from each other.
Force is indirectly proportional to the distance. So, when the distance increases the force of attraction decreases.
Thus, the correct option is B.
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Hạt mang điện q > 0 chuyển động trong từ trường của một dòng điện thẳng dài có cường độ I = 10A như hình. Hạt mang điện chuyển động song song với dây dẫn và cách dây một khoảng 5cm. Vẽ hình và:
a. Xác định cảm ứng từ do dòng điện gây ra tại điểm mà hạt mang điện đi qua.
b. Hạt mang điện chuyển động với tốc độ 104m/s, lực Lorentz tác dụng lên hạt là 8.10-4N. Tính độ lớn của điện tích.
Answer:
I dnt know that language
Explanation:
Why do some "people" still believe that the earth is "flat".
I called my brother in Australia and it was day here, and night there, HOW CAN THE EARTH POSSIBLY BE FLAT, i did a zo,om meeting to prove that it was live. WHAT ARE PE,OPLE TH,INKING!!!
Answer: Members of the Flat Earth Society claim to believe the Earth is flat. Walking around on the planet's surface, it looks and feels flat, so they deem all evidence to the contrary, such as satellite photos of Earth as a sphere, to be fabrications of a "round Earth conspiracy" orchestrated by NASA and other government agencies.
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